Printer paper input trays were developed to support and align paper for feeding to a printer. Paper trays are positioned in a printer feed zone. In operation a paper stack is manually placed on the paper tray. The tray is then securely positioned adjacent the printer feed zone. With the tray in the secured position, the paper stack is adjacent paper picking mechanisms within the printer feed zone, the paper picking mechanisms feeding the top sheet of the paper stack to the printer.
The paper picking mechanisms operate by picking the top sheet from the stack and forcing the sheet into the printer. In some printers, prior to feed to the printer, the top sheet is partially removed from the stack by the paper picking mechanisms. Thus, when the printer finishes a print job, the top sheet of the paper stack in the input tray is slightly removed from the stack, and held by the paper picking mechanisms, ready for feed to the printer.
Between print jobs an operator may desire to extend the paper tray from the feed zone to add more paper to the paper tray, or to insert a different kind of paper. Conventionally, during extension of the paper tray frictional forces on the paper stack from the printer, including a guide rail, and frictional forces between the paper sheets themselves, caused sheets of the paper stack to be disturbed and repositioned out of a vertical trim and aligned stack. Additionally, in printers which pre-feed a top sheet through use of paper picking mechanisms, the top sheet often remained in the paper picking mechanisms upon extension of the paper tray. These problems required an operator to manually pull the top sheet out separately and realign the paper stack after extension of the paper tray, resulting in wasted operator time. In addition, manual pulling of paper from the paper picking mechanisms led to wasted paper because such manual pulling may bend and crease the paper, rendering the paper unusable.